Final answer:
The Z-score for a data point of 100 is -1.6667.
Step-by-step explanation:
To find the Z-score for a data point of 100 given a mean of 135 and a standard deviation of 21, we can use the formula:
Z = (x - mean) / standard deviation
Substituting the values, we get Z = (100 - 135) / 21 = -1.6667
Therefore, the Z-score for a data point of 100 is -1.6667.